[The development of immunity after vaccination of cattle against trichophytosis].

Trials were conducted with 262 one-month-old calves. Good immunity was found to have developed within the period of 21 to 28 days after the administration of the Czechoslovak live vaccine against bovine trichophytosis. After epicutaneous inoculation of a highly virulent culture of Trichophyton verrucosum, performed 28 and 35 days after re-vaccination, no clinical form of trichophytosis was observed to rise in the calves. The same doses of challenge inoculum induced profound trichophytic changes. In the groups of calves artificially infected on the day of re-vaccination and seven days after re-vaccination, the proportions of experimental animals that fell ill were 88.2% and 44.4%, respectively; in the majority of cases, the course of the disease was not so serious as in the controls. Calves challenged 11 to 21 days after the second administration of the vaccines were mostly resistant to experimental infection: slight changes occurred in 15.4 to 7.0% of the tested animals.